硒代胱氨酸对人三阴性乳腺癌细胞的抑制作用

Inhibitory effect of selenocystine in human triple negative breast cancer cells

目的观察硒代胱氨酸（SeC）对三阴性乳腺癌（TNBC）的细胞毒效应，探讨其对TNBC的作用机制。方法选取3种TNBC细胞株，根据不同的实验条件，通过细胞计数试剂盒（CCK-8）法检测SeC对TNBC的抑制作用，通过膜联蛋白V-异硫氰酸荧光素（AnnexinV—FITC）法检测SeC对TNBC诱导凋亡的作用，通过碘化丙锭（PI）染色法检测SeC对TNBC细胞周期的影响。结果SeC对TNBC增殖有明显的抑制作用，该作用随着SeC浓度的升高或共培养时间延长而增强。SeC诱导TNBC发生明显细胞凋亡，同样与SeC存在时间-剂量关系。SeC还可以引起TNBC的S期比例增加，C2／M期比例减少，在20、40μmol／LSeC中尤为明显。10μmol／LSeC与MDA-MB-231共培养24、48、72h后发现：24、48、72h的S期比例与对照组比较有明显升高（P〈0．01）；24h细胞凋亡率与对照组比较差异无统计学意义（P〉0．05），48h与72h细胞凋亡率明显升高（P〈0．01）。结论SeC对TNBC增殖有明显的抑制作用。SeC可以引起TNBC发生明显的S期细胞阻滞及细胞凋亡，并具有明显的时间一剂量效应。SeC诱导MDA—MB-231发生S期阻滞的时间较细胞凋亡早，提示SeC诱导的S期阻滞及细胞凋亡可能为SeC抗癌作用机制的序贯事件。

Objective The aim of this article is to observe the inhibitory effect of SeC for triplenegative breast cancer （TNBC） and investigate the mechanisms. Methods In this study TNBC cell lines were divided into three groups according to the type. Following the protocol, the ceils were incubated with different concentrations of SeC for different periods of time. The inhibitory effect of SeC on the growth of tumor cells was determined employing a cell counting kit-8 （CCK-8） assay. SeC induces cancer cells apoptosis examined by Annexin V-FITC assay. The influence of SeC on tumor cells cycle distribution detected through PI assay. Results SeC has the strongest inhibitory effect to TNBC in a time and dose-dependent manner. Apoptosis rates of TNBC are relative to SeC concentration and co-culture time. Along with the concentration of SeC elevating, proportion of S-phase raises and proportion of G2/M-phase decreases, especially in 20, 40 μmol/L SeC. After SeC culture with MDA-MB-231 in 24, 48 and 72 h, there were significant differences of S-phase proportion between experimental group and control group in 24, 48 and 72 h （P 〈 0.01 ）. There were significant differences of apoptosis between experimental group and control group in 48 h and 72 h （P〈0. 01）, but no difference in 24 h. Conclusion In vitro, SeC obviously inhibit the proliferation of TNBC in a time and dose-dependent manner, through the induction of S-phase arrest and apoptosis, S-phase arrest SeC induced MDA-MB-231 to is earlier than apoptosis. It implies that S-phase arrest and apoptosis are sequential evens of SeC to antitumor.